1. Field of the Invention
The present invention relates to a fluid machinery which is suitable for the compressor or the pump.
2. Description of the Related Art
In the prior art, as a representative example which is closest to a fluid machinery of the present invention as the compressor, there has been a scroll compressor. The outlines of the configuration and the operation of the scroll compressor may be given as follows. That is, a compression chamber can be formed by engaging a spiral body serving as a stationary scroll with another spiral body serving as a rotating scroll and then rotating the rotating scroll such that a volume of the compression chamber can be reduced sequentially from the outer peripheral portion toward the center portion, then the compressed working fluid can be discharged from the compression chamber to the outside via a discharge port provided on the center portion of the scroll compressor.
Since the scroll compressor compresses the working fluid from its outer portion to its center portion along its radial direction, a compressible volume can be determined by the radius of the rotating scroll. For this reason, according to an increase in the compressible volume, such radius has to be increased and thus the overall scroll compressor is also increased in size. In addition, because an inner surface of one spiral body and an outer surface of another spiral body can serve as an inner engaging surface of the stationary scroll and an outer engaging surface of the rotating scroll respectively, the inner engaging surface of the stationary scroll and the outer engaging surface of the rotating scroll must be finished with high precision. As a result, a working cost has been increased, a longer machining time has been needed, etc., so that the scroll compressor has not been desirable in the aspect of workability.
Therefore, it is an object of the present invention to provide a highly efficient fluid machinery capable of expanding a compressible volume without an increase in size and suppressing seal leakage smaller by assuring a stable motion of a moving spiral.
In order to overcome the above problems in the prior art and to achieve the object of the present invention, as a preferred embodiment of the present invention, there is provided a fluid machinery comprising a stationary spiral having an inner engaging surface which rises spirally from its inner periphery to its center portion and has a stepwise sectional shape, a moving spiral having an outer engaging surface which rises spirally from its outer periphery to its center portion and has a stepwise sectional shape, and is rotated upon an axis line relatively to the stationary spiral; a working chamber formed from the outer periphery to the center portion by engaging the outer engaging surface of the moving spiral with the inner engaging surface of the stationary spiral so as to have a reduction in volume; and pushing means for pushing the moving spiral along the axis line.
As another preferred embodiment of the present invention, there is provided a fluid machinery comprising a stationary spiral having an inner engaging surface which rises spirally from its inner periphery to its center portion and has a stepwise sectional shape; a moving spiral having an outer engaging surface which rises spirally from its outer periphery to its center portion and has a stepwise sectional shape, and is rotated upon an axis line relatively to the stationary spiral; a working chamber formed from the outer periphery to the center portion by engaging the outer engaging surface of the moving spiral with the inner engaging surface of the stationary spiral so as to have a reduction in volume; a spiral sealing member provided between the inner engaging surface of the stationary spiral and the outer engaging surface of the moving spiral, for sealing a space between the working chamber and the working chamber; and pushing means for pushing the moving spiral along the axis line.
In the fluid machinery of the present invention, the pushing means pushes the moving spiral to the stationary spiral side as a pushing direction.
In the fluid machinery of the present invention, when the moving spiral is pushed by the pushing means, an upper surface of a bearing portion of the moving spiral is received by a lower surface of a bearing portion of the stationary spiral. According to such fluid machinery, when the moving spiral rotates relative to the stationary spiral while the inner engaging surface is being engaged with the outer engaging surface, the working chamber with a reduction in volume from the outer periphery to the center portion can be formed.
In the fluid machinery of the present invention, since the working volume of the working chamber can be determined along the radial direction and the height direction at that time, the large working volume can be obtained irrespective of an increase of the overall fluid machinery in size. At the same time, since the moving spiral is pushed toward the stationary spiral side by the pushing means, a stable rotational motion of the moving spiral upon the axis line can be ensured even when the deviated load is imposed upon the moving spiral. As a result, the inner engaging surface can firmly engage with the outer engaging surface, so that the efficient working chamber which is capable of preventing seal leakage can be implemented.
In this case, the pressure of the gas such as the suction gas, the compression gas, etc.; may be employed as the pushing means. A uniform pushing force can be applied when such gas pressure is guided to the rear surface of the moving spiral circularly or annularly. At that time, it is preferable that the gas pressure in excess of the suction gas pressure should be applied to the rear surface of the moving spiral as the gas pressure.
In the fluid machinery of the present invention, in order to maintain secure sealing for a long period of time, it is desired that the wear resistance material, the sealing member, or the annular member may be provided on the sliding working surface between the outer upper surface of the bearing portion and the inner lower surface of the bearing portion not to leak the compression gas to the crankshaft side.
In the fluid machinery of the present invention, the moving spiral can be pushed toward the anti-stationary spiral side by the pushing means. As conditions at that time, the rear surface of the moving spiral can be received by the annular receiving portion which is provided on the supporting frame. Otherwise, the sealing member or the annular member can be provided on the sliding working surface of the receiving portion, so that secure sealing can be maintained when different gas pressures are guided to the inside and the outside of the receiving portion. Accordingly, since the rear surface of the moving spiral is pushed toward the anti-stationary spiral side in working operation, the moving spiral can be supported by the annular receiving portion even when the deviated load is imposed upon the moving spiral, and therefore a stable rotational motion of the moving spiral upon the axis line can be ensured. As a consequence, the inner engaging surface can engage with the outer engaging surface without fail, so that the efficient working chamber which is able to prevent seal leakage can be implemented.